M-Lab focuses specifically on the fuel injection process and the subsequent ignition, combustion, and emissions formation processes.

A critical challenge is understanding how these new fuels behave inside an engine. Given the wide variability in fuel properties, particularly for biofuels, there is a clear need for advanced testing and experimental characterization techniques. 

Working closely with our partners in Energy Process Technology and SINTEF Ocean, the laboratory provides what may best be described as applied fundamental understanding of emerging marine fuels. 

The laboratory is continuously being modified and expanded to reflect the rapidly evolving fuel landscape.

Our work bridges the gap between highly fundamental combustion research and fully applied engine testing.

We aim to generate high-quality experimental data that can support both computational model developers working at the fundamental level and engine researchers conducting applied performance and emissions studies.

Flexibility is a key design philosophy of M-Lab, enabling the facility to adapt quickly to new fuels, research challenges, and industry requirements.

Currently, the laboratory operates a Combustion Research Unit (CRU) supplied by FuelTech Trondheim.  

The facility has been developed through many years of collaboration with the company and provides a highly flexible platform for investigating fuel spray formation, ignition processes, combustion behaviour, and pollutant formation under conditions representative of modern marine engines. 

The CRU is a small stainless-steel constant-volume combustion chamber equipped with two fuel injection systems. One injection system uses a diesel common-rail injector for, while the other injection system uses a gasoline direct injector for alternative fuels such as biofuels, methanol and ethanol. Fuel is injected into the chamber and auto-ignites under the high-temperature and high-pressure conditions.  

The combustion chamber can be heated to about 650 °C and pressurised to about 50 bars. Chamber pressure is recorded, and the time between injection and pressure rise is used to determine ignition delay. Furthermore, the chamber pressure can also be post-processed to analyse heat release rates.  

The setup includes fuel- and chamber-pressure sensors, temperature sensors, lab exhaust, external cooling, gas detection alarms, software interlocks, a bursting disc that relieves at 140 bars, and a safety pressure relief valve. With an optical window on the combustion chamber, the CRU also gives the possibility of optical diagnostics and is currently combined with a differential mobility spectrometer for measuring particulate matter formed during combustion.  

Fuel preparation included in the lab means the CRU can handle diesel like fuels, heavy fuel soils, methanol ammonia and many other marine fuels. 

CVCC with optical access and fuel injection system: The primary function of CVCC spray visualisation test rig is to replicate the thermodynamic conditions present within internal combustion engines during fuel injection and combustion. This controlled simulation is essential for accurately observing and analysing spray behaviour under engine-relevant conditions.

The Constant Volume Premixed Combustion Vessel is a constant-volume, pre-mixed combustion test rig built to support detailed optical diagnostics of fuel spray and combustion behaviour under precisely controlled conditions.

It has a cubical internal geometry and is assembled from several modular parts, including a gas exchange system, an injector adapter, corner modules, and two optical quartz windows. These windows allow a range of optical diagnostic techniques to be applied, depending on the specific requirements of a given experiment.

The facility is suitable for both non-evaporative/non-reactive and evaporative/reactive spray studies. For non-evaporative, non-reactive spray studies, the chamber runs in a cold mode: no heating is applied, and the target pressure is reached simply by filling the chamber with compressed air or nitrogen through the gas exchange modules, leaving the gas at ambient temperature.

For evaporative and reactive spray tests, the chamber must first be brought up to temperature, which is achieved through a pre-mixed combustion process. A spark plug mounted in one of the corner modules ignites a gas mixture, raising the internal temperature and pressure to required level ahead of the actual fuel injection event. Corner-module sensors continuously track pressure and temperature throughout this process.

Consistency between tests is maintained by fully purging the chamber and refilling it with a fresh gas mixture ahead of each individual injection. The optical windows are inspected visually and cleaned as needed, based on the clarity of the images being recorded.